When a digital photograph is taken of an image that includes a bright light source, a light vertical line often appears in the digital image. The light vertical line results from “smear” leakage caused by the bright light source. The bright light source can cause smear leakage from an overloaded storage element to an adjacent storage element of an image sensor in a digital camera. FIG. 1 illustrates a digital image 10 that includes a light vertical line 11 caused by smear leakage. In this example, the smear leakage is due to the bright light source of the sun in the real-world image that was photographed. In addition to light vertical line 11, the colors in digital image 10 may also not accurately reflect the colors in the real-world image because the bright light source affects the black level calibration used to correlate digital pixel data to specific colors. For example, the tree in the original photographed image of FIG. 1 may appear in digital image 10 as blue instead of green.
An apparatus is sought for detecting and indicating the presence of smear leakage in an image sensor. An apparatus is also sought that reduces the smear-induced deviation of colors in a digital image from the true colors in the corresponding real-world image.